1. Field of the Invention
The present invention generally relates to the distribution of video signals in a multimedia network and, more particularly, to a low cost, high performance hybrid digital/analog multimedia distribution network which combines the flexibility of digital video and digital networks with the low cost, high bandwidth, and isochronous capabilities of analog video distribution
12. Description of the Prior Art
An all digital network for digital video transmission is either too expensive or too slow to support a large number of video streams. An all analog network, on the other hand, lacks the user interactivity possible with digital video in multimedia applications. Existing local area networks (LANs), such as the 10 Mbps (megabits per second) Ethernet or the 16 Mbps Token Ring, have neither the high bandwidth nor the isochronous transfer capability needed to deliver digital video (and audio) to a large number of workstation clients. Current video compression standards, such as those promulgated by the Moving Pictures Experts Group (MPEG) and the Joint Photographic Experts Group (JPEG) at 30 frames/second, typically require a bandwidth of 1.2 Mbps to 4 Mbps for a bit stream of video cassette recorder (VCR) quality video. Higher speed LANs, such as the 100 Mbps Fiber Distributed Data Interface (FDDI) and the newer FDDI-II and gigabit LANs, are not widely available because they are not yet adopted standards and/or are too expensive. As a result of these limitations, most multimedia applications today are done in standalone workstations and only a few concurrent users can be adequately supported in a network environment.